Compensator for riveting machines



May 21, 1946. w. JOHNDREW i 2,400,758

COMPENSATOR FOR RIVETING MACHINES Filed Sept. 22, 1944 2 Sheets-Sheet 1 w [7 67% 1 K Y a INVENTOR Wu.auR Jouuonew 21, 1946. W.JOHNDREW 2,409,758

COMPENSATOR FOR RIVETINQMACHINES Filed Sept. 22, 1944 2 .heets-Sheetfi \h/il-BUR JoHNoREw BY.

ATTORNEY$ Patented May 21, 1946 UNITED STATES PATENT OFFICE COMPENSATOR. FOR RIVETING MACHINES Wilbur Johndrew, Buffalo, N. Y.

Application September 22, 1944, Serial No. 555,366

12 Claims.

My invention relates in general to compensators and particularly to devices for determining the height of rivet heads and is used in connection with the control means of a riveting machine to terminate the riveting action of such a machine at a predetermined point in the riveting operation.

It is well known to those skilled in the art, that, in some riveting machines, the height of the rivet head is determined by the overall length of the rivet at the completion of the riveting action.

Obviously should there be any variation in the thickness of the workpieces being riveted or variations in the proportions of the rivet, the height of the rivet head will be definitely affected. It is also well known that such variation is prohibitive in certain industries, such, for into a riveting machine and be easily attached to or detached therefrom.

, Moreover, my device is provided with sensitive adjusting means, whereby it may be set to produce a rivet head of a predetermined thickness.

Furthermore, graduations are provided on the adjusting means so that various size rivets may be logged numerically to avoid repeated trial for a rivet head size.

The above objects and advantages have been accomplished by the device shown in the accompanying drawings of which:

Fig. 1 is a front elevation of my device showing it attached to a riveting machine, a fragmentary portion only of the machine being shown;

Fig. 2 is an enlarged longitudinal sectional elevation of the preferred form of my invention, taken on line II-II of Fig. 4. and shown in circuit closing position with an upset rivet in place;

Fig. 3 is a sectional plan view thereof, taken on line III-III of Fig. 2;

Fig. 4 is a reduced sectional plan view thereof, taken on line IV--IV of Fig. 2;

Fig. 5 is a reduced sectional plan view, taken on line V-V of Fig. 2;

Fig. 6 is a fragmentary sectional elevation of a modified form of the invention, taken on line VI.VI of Fig. 7; and,

Fig. '7 is a bottom plan view of the invention of Fig. 6, taken on line VII--VII of Fig. 6.

Referring to Fig. 1, I show the upper portion H) and the lower portion H of a riveting machine. Theseportions are located at the throat of the machine, and the upper portion of the machine carries the riveting ram 12 to which is attached the movable anvil [3. The portion ll of the machine carries the usual height control screw M to which the'stationary anvil I5 is secured by the stud I 6, in well known manner. Suitable means (not shown) are of course provided on the riveting machine for causing the ram to descend and coact with the stationary anvil during the riveting operation.

My. device comprises in general a pressure sleeve 20 which is slidably mounted upon the stationary anvil l5 and which is kept normally in its upper position by means of a pressure sleeve spring 2|. This spring is mounted beneath the sleeve, having one end contacting with the lower surface thereof, and the other end engaging the flange 22-01 the anvil l5. As shown in Fig. 2, to which reference is made, the pressure sleeve is shown as having been moved downwardly 'to the position where the gap I1 between its upper edge and the upper end of the anvil is substantially the same height as the desired thickness of the rivet head, at which time the action of the ram l2 will be terminated. In order to prevent the sleeve from being moved upwardly on the stationary anvil beyond a predetermined point, a spline pin 23 is provided. This pin is carried by and extends laterally through the pressure sleeve and engages a longitudinally extending flattened surface 24 formed on the stationaryanvil 15. Not only does this spline pin together with the flattened surface limit the endwise movement of the pressure sleeve upon the anvil IE, but it also prevents rotation of the sleeve upon the anvil for reasons to be hereinafter described.

The sleeve is provided on its lower end with a collar 25 having a series of equidistantly spaced detent grooves, 26 formed longitudinally in its surface The sleeve is furthermore provided with screw threads 30 for the reception of the casing 3| of the device. This casing is preferably formed with a casing head 32 which is promeans of a helical spring 4!, mounted within the bore. The casing 3| may thus be rotated upon the pressure sleeve definite and predetermined amounts, the screw threads 33 serving .to move the casing axially upon the sleeve to adjust its position relatively thereto in order to determine very accurately the place in the riveting operation where the head will have reachedits predetermined height. Graduations 39 are preferably provided on the casing whereby the device may be logged for various size rivets. As hereinbeiore stated, the spline pin 23 prevents relative rotaof the casing and the collar 42, a lower casing M is provided. This casin is circular in form and is suitably secured to the flange 43 of the collar and the stud ring 45. This casing extends upwardly within the skirt 33 of the casing 3|, and is preferably formed with an opening 62 for the reception of the electrical conduit 63 carrying current to the device. This conduit passes through a suitable aperture (not shown) formed in the collar 42, and it is preferably retained in position by means of a clamp collar 64 held in place by means of a set screw 55 carried by the collar 42. So as to conduct electricity to two of the contact studs 55, contact arms 65 are provided, each of which is secured under one of the studs, as shown in Fig. 4, and leads Hi from the conduit 63 are secured thereto, preferably by soldering.

tion of the sleeve 23 upon the anvil I5 so that the f above adjustments may be conveniently made.

Carried by the anvil flange 22 is a collar 42 which is formed with an inwardly projecting flange 43 for engagement with the upper surface of the flange 22. The collar 42, shown in Fig. 3,

is preferably split at 41, the ends being clamped together by means of a screw 44, whereby the collar is securely attached to the anvil flange.

The flange 53 extends part way across the collar and carries a stud ring 45 of insulating material' This ring is preferably secured to, the flange by means of countersunk screws 45. Carried by the stud ring 45 are three contact studs 58, preferably equidistantly spacedyand secured in place by means of countersunkscrews 51. Only two studs 50 are required as live contacts, but three of them are used so as to provide adequate contact with a contact ring 52.

This contact ring ismounted above'the studs and is carried by and w secured to a pressure ring 53 by means of coun tersunk screws 54. This pressure ring is of insulating material and is mounted to float within the casing 3 I. The ring is pushed downwardly by means of a. plurality of helical springs 55 having their upper ends mounted in recesses 56 formed in' the casing head 32 and their lower ends mounted in recesses '60 formed in the ring 53. The pressure ring 53 is of such a diameter as to engage the shoulder 35 of the casing skirt 3-3 when the pressure sleeve is in its upper'position.

such time'as the contact ring 52 contacts the contact studs 50. As will be clear to those skilled in the art, there islikely to be a slight overtravel of the anvil I3 and the riveting ramlZ after the ring 52 has made contact with the contact studs,

and to compensate for this overtravel, the springs 55 will permit the sleeve to travel downwardly after movement of the ring 52 has been stopped thus preventing damage to the device. This amount of overtravel is of course compensated for in the adjustment of the device for any given 7 rivet head height.

So as to enclose the space between the skirt 33 When two sheets 51 shown in Fig. 2 are to be riveted together by means of my device, they are placed between the riveting anvil i3 and the pressure sleeve 20 resting upon the latter which is normally in its upward extended position. The operator causes the ram to be moved downwardly by well known means which causes the workpieces to be pressed against the pressure sleeve causing it to move downwardly against the tension of the spring 2|. This will bring the body part of the rivet in contact with the stationary anvil l5, and further downward movement of the riveting anvil [3 will bring about the upsetting of the rivet, as clearly shown in Fig. 2. The device is adjusted so that when the rivet head thus formed is of predetermined thickness, the contact ring 52 will engage the two live contact studs 5!), thus closing the circuit (not shown) and stopping the operation of the ram. Should delay occur in the stopping of the riveting operation after the above mentioned circuit has been closed, the spring pressed ring 53 will compensate for such further movement of the pressure sleeve by moving upwardly in the casing 3| against the tension of the springs 55, as hereinbefore described. Owing to the convenient adjustability of my device, any such overtravel may be easily compensated for.

Referring now to the form of invention shown in Figs. 6 and '7, the stationary anvil is represented at 1! upon which is mounted the pressure sleeve l2. This sleeve is preferably formed integrally with a hollow casing 13, and is formed with a recess l5. Within the recess 14 is mounted an insulating ring 15 which is suitably secured in place and which carries the contact plates 16 of the device. These contact plates are made of resilient material suitably secured to the ring at one end and formed with contact tips at their free ends. They are bent downwardly as shown in Fig. 6, and leads 8| coming from a conductor wire 82 are suitably secured under the plates to conduct electricity thereto.

The stationary anvil H is formed with the usual'anvil flange 83 and the usual stud 84 for securing the anvil to the height control screw of the riveting machine. An anvil ring 85 is mounted upon the stationary anvil H and has a flange 85 which extends over and is permanently secured to the anvil flange 83. The outer periphery of this anvil ring is screw threaded for engagement with an adjusting ring 90. The adjusting ring is formed with an upstanding flange 9! within which is suitably secured a ring 92 of insulating material. Secured to the upper surface of the ring 92 is a contact ring 93 with which the points 85 of the contact plates 13 contact when the pressure sleeve 12 is moved downwardly upon the stationary anvil I8, such contact being made at the end of the riveting operatin. A helical spring 94 serves to keep the pressure sleeve normally in its upper position as shown in Fig. 6. The adjusting ring 9%] is preferably knurled so that it may be conveniently rotated upon the anvil ring 85, and graduations are provided so that its position may be indicated.

Obviously, when this form of my invention is to be used, the pressure sleeve 12 is forced downwardly upon the anvil H in a manner similar to the other form of invention, and when the sleeve has reached the point in its travel at which the device has been previously adjusted, the contact plate 16 will make contact with the contact ring 93 and stop the ram action. Any overtravel in this form will be compensated for by the resiliency of the contact plates 15.

While I have shown and described my device in detail, it is obvious that the inventive principles disclosed herein may assume other physical embodiments without departing from the spirit or scope of the invention set forth by the appended claims.

Having thus described my invention, what I claim is:

l. The combination in a riveting machine. having a stationary anvil and coacting movable anvil, of a compensator comprising a pressure sleeve mounted upon said stationary anvil for longitudinal movement thereon, spring means for keeping said sleeve in its normal upper position, a casing carried by said pressure sleeve, and contact means mounted within said casing and actuated upon downward movement of said pressure sleeve, said casing being adjustable axially relative to said sleeve for adjusting the normal distance between the contact means.

2. The combination in a riveting machine,

having a stationary anvil and a coaeting movable anvil, of a compensator comprising a pressure sleeve mounted upon said stationary anvil for longitudinal movement thereon. spring means for keeping said sleeve in its normal upper position, a casing carried by said pressure sleeve, contact means mounted within said casing and actuated upon downward movement of said pressure sleeve, index means carried by the pressure sleeve and casing for permitting predetermined graduated axial. adjustment of; said casing on said sleeve, and means for adjusting the normal distance between the contact means.

, 3. The combination in a riveting machine, having a stationary anvil and a coacting movable anvil, of a compensator comprising a pressure sleeve mounted upon. said stationary anvil for longitudinal movement thereon, spring means for keeping said sleeve in its normal upper position, a casing carried by said pressure sleeve, contact means mounted within said casing and actuated upon downward movement of said pressure sleeve, index means carried by the pressure sleeve and casing for permitting predetermined graduated axial adjustment of said casing on said sleeve, spline means carried by said pressure sleeve and said stationary anvil for preventing relative rotation thereof, and means for adjusting the normal distance between the contact means.

4. The combination in a riveting machine, having a stationary anvil and a coacting movable anvil, of a compensator comprising a pressure sleeve mounted upon said stationary anvil for longitudinal movement thereon, spring means for'keeping said sleeve in its normal upper position, a casing carried by said pressure sleeve',-a spring pressed contact ring carried by said cas ing, a plurality ofcontact members carried by said stationary anvil and engageable with said contact ring upon downward movement of the latter, and means for adjusting the casing axially upon the pressure sleeve to alter the relative position of the contact ring with respect to the contact members.

5. The combination in a riveting machine, having a stationary anvil and a coacting movable anvil, of a compensator comprising a pressure sleeve mounted upon said stationary anvil for longitudinal movement thereon, spring means for keeping said sleeve in its normal upper position, a casing carried by said pressure sleeve, a spring pressed contact ring carried by said casing, a collar carried. by said stationary anvil and located beneath said casin a plurality of contact studs carried by said collar and engageable with said contact ring upon downward movement of the latter, and means for adjusting the casing axially upon the pressure sleeve to alter the relative position of the contact ring with respect to the contact studs.

6. The combination in a riveting machine, having a stationary anvil and a coacting movable anvil, of a compensator comprising a pressure sleeve mounted upon said stationary anvil for longitudinal movement thereon, spring means for keeping said sleeve in its normal upper position, a casing carried by said pressure sleeve, a spring pressed pressure ring resiliently mounted in said casing, said casing having an inwardly having a stationary anvil and a coacting movable anvil, of a compensator comprising a pressure sleeve mounted upon said stationary anvil for longitudinal movement thereon, spring means for keeping said sleeve in its normal upper position, a casing carried by said pressure sleeve, a spring pressed pressure ring resiliently mounted in said casing, said casing having an inwardly extending flange forming a shoulder for engagement with said pressure ring to limit its downward movement within said casing, a contact ring carried by said pressure ring, a collar carried by said anvil beneath said casing, a ring of insulating material carried by said collar, and a plurality of contact studs carried by said ring and engageable by said contact ring when the latter moves downwardly.

8. The combination in a riveting machine, having a stationary anvil and a coacting movable anvil, of a compensator comprising a pressure sleeve mounted upon said stationary anvil for longitudinal movement thereon, spring means for keeping said sleeve in its normal upper position, a casing carried by said pressure sleeve, 2. spring pressed pressure ring resiliently mounted in said casing, said casing having an inwardly extending flange forming a shoulder for engagement with said pressure ring to limit its downward movement within said casing, a contact ring carried by said pressure ring, a collar carried by said anvil beneath said casing, a ring of insulating material carried by said collar, a plurality of contact studs carried by said ring and engageable by said contact ring when the latter moves downwardly, and means carried by said sleeve and said casing for adjusting the axial relationship of the casing upon the sleeve. 7

9. The combination in a riveting machine, having a stationary anvil and a coacting movable anvil of a compensator comprising a pressure sleeve mounted upon said stationary anvil for longitudinal movement thereon, spring means for keeping said sleeve in its normal upper position, a casing carried by said pressure sleeve, contact means mounted within said casing and actuated upon downward movement of said pressure sleeve, and a lower casing carried by said stationary anvil and in telescopic arrangement with said casing.

10. The combination in a riveting machine,

having a stationary anvil and a coacting movable anvil, of a compensator comprising a pressure sleeve mounted upon said stationary anvil for longitudinal movement thereon, spring means for keeping said sleeve in its normal upper posi tion, a casing carried by said pressure sleeve, a spring pressed pressure ring resiliently mounted in said casing, said casing having an inwardly extending flange forming a shoulder for engagement with said pressure ring to limit its downward movement within said casing, a contact ring carried by said pressure ring, a collar carried by said anvil and located beneath said casing, a ring of insulating material carried by said collar,

'a plurality of contact studs carried by said ring and engageable by said contact ring when the latter moves downwardly, and a lower casing surrounding said ring of insulating material and extending up within the upper casing.

11. The combination in a riveting machine, having a stationary anvil and a coacting movable anvil, of a compensator comprising a pressure sleeve mounted for longitudinal movement upon said stationary anvil, spring means for maintaining said sleeve in its normal upper position, a casing carried by said sleeve, electrical contact plates enclosed Within said casing, a contact ring carried by said stationary anvil for engagement by said contact plates, and means carried by said stationary anvil for adjusting said ring.

12. The combination in a riveting machine, having a stationary anvil and a coacting movable anvil, of a compensator comprising a pressure sleeve mounted for longitudinal movement upon said stationary anvil, spring means for maintaining said sleeve in its normal upper position, a casing carried by said sleeve, electrical contact plates enclosed Within said casing, 21 contact ring carried by said stationary anvil for engagement by said contact plates, an adjusting ring carrying said contact ring and mounted on said stationary anvil, and means carried by said adjusting ring and said anvil for moving said contact ring to adjust its axial relation to said anvil.

WILBUR JOHNDREW. 

